Flowmaster catback + 440 RWHP car
Tech Resident
Joined: Jan 2006
Posts: 5,117
Likes: 3
From: Philly
There are other catbacks that flow better than Flowmaster, but I've seen mixed results. I've seen dynos where people open their cutout and gain 20rwhp on a H/C car. I have also seen dynos where people open their cutout and gain 2rwhp on these cars. If you open a cutout on your car, you'll probably see a 10-15rwhp gain. However, you'll see a ~10rwhp gain on nearly ANY catback vs. an open cutout with the exception of an SLP Loudmouth I. Long story short, if you like the sound of the catback, put an electric cutout on your car. Keep it closed when driving around and when you're going to race, open it up. Best of both worlds.
Tech Resident
Joined: Jan 2006
Posts: 5,117
Likes: 3
From: Philly
I've done the test back to back on a heads/cam car. Flowmaster robbed 22 rwhp vs. a cutout on a 460 rwhp car. Switched on a Hooker Aerochamber, and picked back up the 20 rwhp.
The Flowmaster sounds decent (if you like sounding like a pickup truck), but is quite possibly (aside from Corsa or B&B Tri-Flow) the worst flowing catback and/or muffler available for F-bodies.
The Flowmaster sounds decent (if you like sounding like a pickup truck), but is quite possibly (aside from Corsa or B&B Tri-Flow) the worst flowing catback and/or muffler available for F-bodies.
I had to laugh at this. Not because you're saying Flowmaster doesn't flow as well as other catbacks, but because you lumped Corsa in with Flowmaster. Corsa is by far one of the BEST flowing catbacks on the market. It'll outflow a GMMG, I bet you. My car went .2 slower with the cutout open vs. Corsa. I turned back to back 13.60's when my car was lid/catback only with 2.73's with a Corsa catback. I added a cutout and I couldn't turn any better than a 13.79 over the course of 2 nights and 5 track runs. To this day, even after my headers and high flow cats have been installed, my car feels more sluggish with the cutout open. True, it has a lot to do with the tune, but to say Corsa flows poorly is to ignore the facts. I've seen dynos where people picked up literally 2rwhp peak vs. Corsa with an open cutout. And that doesn't take into account the horsepower they lost down low. That's only peak.
TECH Apprentice
Joined: Jun 2007
Posts: 355
Likes: 0
From: Raytown,MO
Dude read the post before that’s the same graph I was talking about the one where I said there was only one person that posted a legit graph and he only lost 8hp from a open cut-out to the flowmaster and it was all top end power so how is it owned you bodied yourself for not reading the prior post stupid. Like the guys below says he lost 3hp when he did the test I just want to see the proof to prove the claims thats all, like I said before if you think the flows are that much of an issue just get a cut-out which will out flow any cat-back and you wont spend 300+ bucks for a new cat-back and this is not english class so **** proper grammar.
Launching!
Joined: Apr 2006
Posts: 213
Likes: 0
From: Back to Newport News
I'm the guy that posted the dyno graph that gained 8rwhp over my flowmaster CB. Choco, your a well informed guy, so re-read that post about the Corsa catback. The guy put his statement in paranthesis() about Corsa, and he said "aside from these.." which excluded Corsa. Not tryin 2 bust ur *****, just tryin to bring some attention to that post that was misread by some of us.
Tech Resident
Joined: Jan 2006
Posts: 5,117
Likes: 3
From: Philly
I'm the guy that posted the dyno graph that gained 8rwhp over my flowmaster CB. Choco, your a well informed guy, so re-read that post about the Corsa catback. The guy put his statement in paranthesis() about Corsa, and he said "aside from these.." which excluded Corsa. Not tryin 2 bust ur *****, just tryin to bring some attention to that post that was misread by some of us.
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Launching!
Joined: Apr 2006
Posts: 213
Likes: 0
From: Back to Newport News
No, Damian meant that Flowmaster, Corsa and B&B Triflow are the worst flowing catbacks for our cars. He's saying Flowmaster is the worst aside Corsa and B&B, meaning they may be even worse than Flowmaster. I know that's not true as I've seen plenty of proof that Corsa flows very well. I bought my car with a Corsa on it, and I have basically full bolt-ons and a cutout, so I'll be getting a tune within the next month or so. I'll be sure to post up a dyno of how Corsa flows with the cutout open and closed
Cool let us know your results!
I am not one for cutouts, so with a large cam, a mid leaghth headers, whats a good catback? My stock bolt on car has LT's and ORY and with a LM1 was wayyyy too loud, now with a magnaflow sounds ok.
